Test strip



H. VOLLMER March 31, 1942.

TEST STRIP RF, n 0 7% W 2 H w N A. a? H Filed Jan. 30, 1940 Fl6.l.

Patented Mar. 31, 1942 ,UNITED STATES PATENT OFFICE 2,278,339 'rss'r- STRIP Hermann Vollmer, New York, N. Y. Application January 30, 1940, Serial No. 316,310

3 Claims.

This invention relates to patch test strips for human beings and is more particularly directed to patch test strips to determine relative skin sensitivity of individuals exhibiting positive reaction.

This application is a continuation in part of my application Serial No. 137,990 filed April 20, 1937, Patent No. 2,190,745 of February 20, 1940. As pointed out in that application, my patch test strips are utilized to indicate the presence or absence of a tuberculousinfection in the individual being tested. These strips operate very efficiently and conveniently without causing the pain of some of the other methods used for tuberculin testing, and also minimize the dangers of focal or general constitutional reactions such as may occur when tuberculin in injected intraor sub-cutaneously and suddenly brought into the circulation. Y

The reactions obtained with my patch test strips are so sensitive that I have found that I may use my patch tests in a form which determines quantitatively the degree of skin sensitivity and which may also be used in a form of patch therapy wherein tuberculin is applied by means of patches for slow absorption through the skin.

In the drawing, I have shown for illustrative purposes, some of the details of my invention.

Fig. 1 represents a plan view of one of my patch test strips;

Fig. 2 shows in elevation and somewhat diagrammatically a human limb to which my patch test strip has been applied and removed with the skin reactions indicated;

Fig. 3 is a perspective of an enlarged portion of a patch test strip; and Fig. 4 is a segmental plan view of a modified patch test strip.

As shown in the drawing, the patch test strip comprises a base I of any suitable adhesive strip. Adhering to the adhesive side of the strip are spaced patches 2, 3, 4, 5 and 6 made up of squares of a fine-grained highly absorbent material presenting a substantially continuous exposed surface, e. g. filter paper. As shown in greater detail in Fig. 3 a patch test strip may comprise a cloth or other suitable base 1 carrying an adhesive layer 8 on one face thereof.

To prepare the patch test strips, sheets of the absorbent material, preferably filter paper, are saturated with solutions oftuberculin. For this purpose I may use old tuberculin from synthetic media which may or may not contain the ground bodies of the tubercle bacilli. The filter paper or other suitable absorbent material is thoroughly air-dried in a suitable dustless cham-.

ber or housing. When the sheets are dry, they are cut into patches or squares about 1 cm. square and are then applied'by means of forceps or the like to the adhesive face of the strip. The patches are spaced at least 1 cm. apart. It will be apparent that the strips and patches may be of any desired practical length, shape and size as required for any particular use.

If the patch strip is to be utilized for specific allergometric tuberculin sensitivity test, the patches which are used contain gradually decreasing tuberculin concentrations. Thus in the strip shown in Fig. 1, patch 2 may contain full strength tuberculin. Patches 3, i, 5 and 6 may contain, respectively, /4, ,4 and 0 strength tuberculin. These patches are prepared in accordance with the general method described except that in the respective cases, the absorbent sheets are saturated with tuberculin solutions of the desired strength.

In utilizing my patch test strips, I first prefer to clean the skin to which the strip is to be applied, with a material such as ether. To the cleaned area I apply the adhesive side of the sternum or transversely over the upper edge of the trapezius or at any other suitable place on the body. The strip is allowed to remain about forty-eight hours and is then removed. While the results of the test may be read immediately after removal of the strip, it is preferable to read the reaction after about twenty-four to fortyeight hours after removal of the strip in order to permit fading out of any unspecific skin redness and also since the additional time permits intensification oi the tuberculin reaction. Where a positive reaction is obtained, there appear squares of clearly defined redness with acorn-like follicular elevations.

Fig. 2 shows a characteristic positive reaction In this figure the limb is designated by 9. Square I2 represents a reaction to full strength tuberculin. Square 43 represents a reaction to Square I4 shows a reaction to-Ai strength strength tuberculin.

tuberculin and square I5 shows a reaction to 0 strength tuberculin. The patch containing Vino strength tuberculin gave a negative reaction. The degree of,reaction obtained is a function of the concentration of tuberculin applied and the clinical results obtained in practice have borne this out.

As hasbeen pointed out, the patches may be of any desired shape or. size. In Fig. 4 there is illustrated a convenient modification of the patch made in the form of a cross. These patches are designated as l6 and I1. For comparative purposes the dimensions of the cross patch are modified so that the area of this patch is approximately 1 square cm. In use, the cross patches, in the case of positive reactions, will give a clearly defined skin redness corresponding generally with the shape of the patch.

Since the tuberculin contained in the patch is dry, the strips may be stored for long periods of time without deterioration. In order to permit easy handling of the patch strips, the adhesive side carrying the patches may be covered with stiff gauze. Prior to use, the gauze is stripped from the adhesive surface and the test strip is to the immediate vicinity of the patch. The ab- :1.

sence of undue spreading of the tuberculin over the surface of the skin serves very effectively to prevent the occurrence of focal and general constitutional reactions. with their undesired attendant dangers.

My patch strips are also useful in tuberculin therapy since the strip containing several patches with gradually increasing concentrations of tutuberculin.

is of the same composition as the tuberculin solution used for the saturation of the test patches except that the control contains no tuberculin.

The tuberculin solution used for impregnating the patches may be of any suitable type. Thus I may use the tuberculin prepared in a growing medium containing glycerine and broth or glycerinc and some synthetic growing medium.' This type tuberculin is customarily referred to as old I may also use crystalline or pure tuberculin obtained from any suitable source but in this case the aqueous tuberculin solution is prepared -and glycerine should be added since small amounts of glycerine in the tuberculin are necessary for best results. Regardless of the type tuberculin used, the patches are prepared as previously described and are dried so as to obtain the dry tuberculin. The dry patches adhere dirtectly to the adhesive surface of the adhesive s rip.

It is also possible to utilize the present invention by preparing a strip carrying patches of various other materials suitable for skin .testi'ng. Thus I may prepare a combination patch test strip carrying patches containing dry-tuberculin, dry diphtheria toxin (Schick test), allergens or the like, with suitable control patches. By

means of my patch test strips I may also utilize 1 sorbent material adhering to the adhesive face berculin may be applied to the skin to permit the tuberculin to be absorbed very slowly and in gradually increasing amounts through the skin. The accurate control of area and dosage permitted by the patch strips is such as to avoid dangerous reactions while permitting rapid, economical and technically simple procedure. The tuberculin patch therapy apparently relies for its results upon desensitization.

The patches used should be of a highly absorbent material sufficiently strong in thin patches to permit handling and of such a nature as to present a substantially continuous surface to the skin. I have found thin filter paper exceptionally well suited for this purpose although I may use other thin absorbent materials such as certain types of thin and closely woven cloth, e. g. finely textured cotton, linen or silk having physical properties similar to the filter paper. A single layer of such a patch is suificien't.

While the use of control patches is not necessary, there may be some instances in which the use thereof is desirable as a check and in such cases I may apply to the patch test strip one or more patches of the same absorbent material except that th control patches are saturated only with glycerine-bouillon. The glycerine-bouillon of said strip, and tuberculin substantially evenly absorbed by each of said patches in such amounts that said patches contain tuberculin in various concentrations thereby enabling by one single test quantitative determination of the sensitivity of the skin to tuberculin. v

2. Allergometric patch test strip comprising .a length of adhesive material, a series of filter paper patches directly adhering to the adhesive face of said adhesive material, and tuberculin substance substantially evenly absorbed by said patches in such a manner that the amount of the tuberculin substance carried by one of said patches is differing from the amounts carried by the other patches, thereby enabling with one single test quantitative determination of the sensitivity of the skin to tuberculin.

3. Allergometric patch test strip comprising a length of adhesive material, a series of patches of thin filter paper directly adhering to the adhesive face of said adhesive material, tuberculin sub-stance absorbed by said thin filter paper patches in such a way that each of said patches is carrying a different amount of said dry tuberculin substance varying in the ratio of about 1:1/2:1/4:1/20:l/100 per unit of exposed surface, thereby enabling by one single test quantitative determination of the sensitivity of the skin to tuberculin.

HERMANN VOLLMER. 

